Dental x-rays linked to most common brain tumour

Washington, April 10 (IANS) Frequent dental x-rays have been linked with higher risk of developing meningioma, the most commonly diagnosed primary brain tumour, says a new study.

The findings suggest that moderate use of this form of imaging benefits some patients, although dental x-rays may be necessary in particular cases.

Dental x-rays are the most common synthetic source of exposure to ionizing radiation for individuals, the primary environmental risk factor for developing meningioma, the journal Cancer reports.

Elizabeth Claus, of Yale University School of Medicine in New Haven and Brigham and Women's Hospital in Boston, and her colleagues studied information from 1,433 patients diagnosed with meningioma.

"The study presents an ideal opportunity in public health to increase awareness regarding the optimal use of dental x-rays, which unlike many risk factors is modifiable," said Claus, according to an Yale statement.

They were aged between 20 and 79 years -- natives of Connecticut, Massachusetts, North Carolina, the San Francisco Bay Area, and eight counties in Houston, Texas -- between May 1, 2006 and April 28, 2011.

The investigators also studied information from a group of 1,350 individuals who had similar characteristics but who had not been diagnosed with a meningioma.

Over a lifetime, patients with meningioma were more than twice as likely as the second group to report having ever had a bitewing exam, which uses an x-ray film held in place by a tab between the teeth.

Individuals undergoing bitewing exams on a yearly or more frequent basis were 1.4 to 1.9 times as likely to develop meningioma as controls. (Risks differed depending on the age at which the exams were done).

An increased risk of meningioma was also linked with panorex exams (which are taken outside of the mouth and show all of the teeth on one film) taken at a young age or on a yearly or more frequent basis.

Individuals who reported receiving these exams when they were younger than 10 years old had a 4.9 times increased risk of developing meningioma.